Banquo asks his son, Fleance, "How goes the night, boy? (2.1.1). Thus opens the scene which ends with Macbeth going to murder his King. Before he goes to bed, Banquo speaks with Macbeth, who suggests they discuss the witches, and that when they do, some "honor" might come Banquo's way, but Banquo is suspicious of
Macbeth's motives. [Scene Summary]

"Banquo and Donalbain! Malcolm! awake!" (2.3.75), Macduff calls out, after discovering the body of King Duncan. Banquo has only one speech in this part of the scene. When Lady Macbeth expresses shock that the murder has taken place "in our house," Banquo says that it is "Too cruel any where" (2.3.88), and then pleads with Macduff to say that King Duncan has not been murdered. Later in the scene, Banquo takes control of the situation by proposing that they hold a meeting to consider the murder of the King. We never hear of that meeting again, but apparently its
result is that Macbeth is named king. [Scene Summary]

Macbeth doesn't tell his wife that he has arranged for the murder of Banquo, but she sees that something is eating at her husband. After Banquo has gone on his ride, she speaks with Macbeth and tries to persuade him to put the past behind him and to act nice to their guests. Bitterly, he tells her that they need to act particularly nice to Banquo:

His point is that just the fact that Banquo is alive makes them unsafe, so they have to make nice to Banquo, no matter how they really feel. He hates the idea, and it's one of the reasons he's having Banquo murdered. [Scene Summary]

The night that Banquo is murdered, Macbeth gives a banquet for his nobles. Things have barely gotten started when First Murderer comes to the door to tell Macbeth that Banquo is dead, that "safe in a ditch he bides, / With twenty trenched gashes on his head" (3.4.25-26). Macbeth returns to his guests and, in a show of supreme hypocrisy, praises Banquo and wishes he were at the banquet. Ironically, he gets his wish. As Macbeth starts to sit among his guests, he finds that the Ghost of Banquo has taken his place. The ghost nods at Macbeth, as though to say "you did this." Macbeth betrays his fear, and the ghost leaves, only to return when Macbeth proposes a toast to his good friend Banquo. [Scene Summary]